Buick 1998 Century Owner's Manual page 233

Rear Towing
Using a towing dolly for your drive wheels is
recommended if your vehicle is towed more
than 500 cumulative miles (800 km) or exceeds
50 mph (80 km/h).
NOTICE:
Do
not tow with sling-type equipment or the rear
bumper valance will be damaged. Use wheel-lift
or car-carrier equipment. Additional ramping
may be required for car-carrier equipment. Use
safety chains and wheel straps. Use the T-slots for
car-carrier securing.
Towing
a
vehicle over rough surfaces could
damage a vehicle. Damage can occur from
vehicle to ground or vehicle to wheel-lift
equipment. To help avoid damage, install
a
towing dolly and raise the vehicle until adequate
clearance is obtained between the ground and/or
wheel-lift equipment.
Do not attach winch cables or J-hooks to
suspension components when using car-carrier
equipment. Always use T-hooks inserted
in T-hooks slots.
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